Treatment of steel sheets



April 19, 1932.

H E. SHELDON TREATMENT OF STEEL SHEETS Y Fild Sept. 2a, 1929 G @QSU INVENTOR Patented Apr. 19, 1932 UNITED STATES PATENT-OFFICE HARRY E. SHELDON, OF PITTSBURGH, FENNSYLVANIA, ASSIGNOR TO ALLEGHENY STEEL COMPANY, A CORPORATION OF PENNSYLVANIA TREATMENT OF STEEL SHEETS Application filed September 26, 1929. Serial No. 395,221.

This invention relates to a process of treating steel sheets such as, and in particular, silicon steel sheets for producing sheets of improved electrical properties, which properties are uniform andpredeterniined so that they may be duplicated.

Much difiiculty has been experienced in obtaining desirable electrical properties in steel sheets not only because the electrical properties are not as great as might be desired, but also because these properties were not uniform and hence it was an impossibility to duplicate sheets, which had been found to be desirable, in order to replace or repair electrical installations containing such sheets.

It is obviously a great advantage topred'etermine the electrical properties of the finished sheets so that uniformity can be attained with consequent ability to duplicate any particular sheets.

It is, accordingly, one object of my invention to so treat steel sheets as to obtain predetermined electrical properties which are uniform and which can, therefore, be duplicated.

It is another object of my invention to carry out certain stepsiin the process of manufacturing such sheets and in repeating said steps in the same order.

It is a further object of my invention to normalize, clean, and dry vertically suspend ed sheets and then to cold roll the same and thereafter to repeat said steps in the same order.

A still further object of the invention is to normalize, clean, dry and cold roll steel sheets, to repeat said steps in the same order, and'fin ally to shear and roller level the sheets.

Other and further objects andadvantages of the invention will either be apparent hereinafter or will be pointed out as the description proceeds.

In the drawings, showing diagrammatically the steps in the present process;

Figure 1 lllustrates the first normalizing,

, pickling, rinsing and drying steps;

Fig. 2 is a vertical cross section through the pickling chamber of Fig. 1;

Fig. 3 is a vertical cross section through the rinsing chamber of Fig. 1-;

Fig. 4 is a horizontal cross section through I the drying chamber of Fig. 1;

Fig 5. is a representation of a plurality of four-high cold rolling mills;

Fig. 6 is a representation of the second normalizing, pickling and rinsing steps;

Fig. 7 is a representation of the second dryin g step following along after the second rinsing step of Fig. 6;

Fig. 8 is a horizontal cross section through the drying chamber of Fig. 7 and Fig. 9 is a representation of the final cold rolling, shearing and leveling steps.

Referring to the drawings in detail and first to Fig. 1, it will be seen that the steel sheets 10 are conveyed by means of aconveying device 11, first, through a normalizing chamber 12, which step follows a previous hot rolling step. In this normalizing chamber, the sheets are quickly and uniformly raised to a comparatively high temperature, for example, about 1800 to 1950 F., for the usual purposes. I

The sheets are next led in the same position through a pickling chamber 13 having a pump or fan device 14 forcing the pickling liquid through the pipe system 15, and out through a plurality of spray nozzles 16 from which the pickling liquid impinges upon all sides of the sheets 10 so as thoroughly to pickle them, and, at the same time, to cool them, since'the pickling liquid is relatively cold compared to the temperature at which the sheets leave the normalizing chamber 12.

From the pickling chamber, the sheets, still in a vertical position, I are conveyed through a rinsing chamber 17 which may be provided with the same type of fluid sprinkling system as the pickling chamber, but, of

course, the liquid passing therethrough is a still vertically suspended, are conveyedinto and through a drying chamber 18. This chamber is heated electrically as at 19 to a moderate temperature sufficiently high to warm the sheets and to assist in driving off any liquid. A suction fan or pump device 20 is provided to assist the dryingby removing the vapors as they are formed.

-The sheets are then removed from the conveying device and are placed in a horizontal position and, as shown, in Fig. 5, led through a plurality of four-high cold rolling mills 21 where a further reduction in the gauge of the.

sheets occurs.

The sheets are then again vertically susrinsing and drying chambers and the last properties will be improved and of mentioned cold rolling step require no detailed explanation as they may be of the same or sim-ilarnature as the previously eX- plained chambers 12, 13, Hand 18 and tlie cold rolling mills 21. The-pipe systems with their spray nozzles and pump .or fan devices and their electrical heating systems are designated by the same numerals as the same elements .have already been designated in the first mentioned s et of steps and chambers, thus indicating the same or similar nature thereof.

After "the horizontally disposed sheets have been passed through the final cold rolling and reducing 'mills they are sheared to desiredsize as at 27 and then roller leveled and smoothed as at 28 and finally inspected and oiled.

The above represents a particularly efficient series of steps which may follow any given hot rolling step in order to finish the sheets in such a manner that their electrical redetermined uniformity, so that sheets 0 similar characteristics can be duplicated at any time required by proper control of the apparatus which, as is apparent, lends itself to accurate and uniform control. d

It is obvious that various changes and modifications maybe made in the steps such as by varying the temperatures and lengths of the various chambers or by adjusting the cold rolling mills to give a desired and predetermined reduction in size at those points.

. It is further to be understood that either or both of the rinsing steps can be carried out with water and/or a neutralizing medium to eliminate the acidic character of any adhering pickling liquid so as to positively prevent deterioration of the sheets at any subsequent time. The drying step can be carried out at any desired temperature but prefer ably not at such a high temperature as to affect the characteristics of the product resulting from the previous normalizing and cleaning steps, and merely as an illustrative temperature for the drying chamber a heat of, say, 100 to 200 F. can be used.

What I claim as new and desire to secure by Letters Patent is '1. In a process of manufacturing silicon steel sheets, the steps of normalizing previously hot rolled vertically suspended sheets, pickling, rinsing and drying the same, cold rolling said sheets, and repeating said steps on the thus treated sheets.

2. In' a process of manufacturing silicon steel sheets the steps subsequent to a previous hot rolling of passing the sheets suspended from a conveyer vertically through anormalizing chamber where they are quickly and uniformly raised to a temperature of about 1800-1950 F.; leadin them in the same position through a pic 'ling chamber provided with means for forcing pickling liquid on all parts of said sheets, simultaneously pickling and cooling them; conveying them through a rinsing chamber provided with means for impinging rinsing liquid on all parts of said sheets, thereby thoroughly scrubbing said sheets and removing any adhering scale and pickling liquid; conveying the vertically suspended sheets into and through an electrically heated drying chamber where they are subjected to moderate heat and suction to dry them, removing them from the conveying device and placing them in a horizontal position in which they are passed through a plurality of four-high cold rolling mills for further reducing the gauge of the sheets; repeating said foregoing steps; shearing to size; roller leveling; inspecting and oiling said sheets.

3. In a process of manufacturing silicon steel sheets of uniformly high and reproducible electrical properties the steps of quickly and uniformly raising such sheets to a temperature of about 18001950 F., forcing pickling liquid onall parts of the sheets thereby simultaneously pickling and cooling them, forcing rinsing liquid on all parts of the sheets to scrub them and remove any adhering scale and pickling liquid, subjecting said sheets to the action of moderate heat and a partial vacuum, reducing the gauge of the sheets, repeating the same steps in the same order under substantially identical conditions, shearing to size, roller leveling, inspecting and oiling.

In testimony whereof, I have hereunto subscribed by name this 24th day of Sept, 1929.

r HARRY E. SHELDON. 

